1. Field of the Invention
A retraction tube for use with a capless spinal screw which allows for the rotation of the screw locking body within, and relative to, the retraction tube. In another embodiment, a retraction tube for use with a capless spinal screw which attaches rigidly to said screw and is dimensioned to permit rotation of said tubular attachment relative to a fixation element.
2. Description of the Related Art
The placement of spinal screws is a common surgical procedure. There is a need to reduce the size of the incision necessary for the placement of such screws. Small tubular tissue retractors have been used to minimize incision size. More recently, tubular attachments have been developed which attach to the screws themselves, performing tissue retraction during the act of screw placement. Typically, the screws are engaged into bone, while the retraction tubes protrude upward through the skin. At this point a fixation element, typically a metallic rod, is placed either through or adjacent to the retraction tubes in order to engage the screws. Typically, a locking cap is then placed through the tube to lock the fixation element to the screws. As demonstrated in the prior art, such tubes attach rigidly to the screw body and do not permit the rotation of the screw body needed to perform locking of the fixation element to the screws.
Recently, there has been the development of capless spinal screws which utilize rotation of the screw body to achieve locking of the fixation element to the capless screws. Current retraction tubes are not capable of being used with capless screws. Since capless screws require rotation of the screw body in order to perform rod locking, an improved retraction tube is needed which allows for rotational screw locking to take place within the tube.